How thick are the spacers? Subtract that thickness from the offset of the GLX wheels. The stock B4 TDI 14 inch wheels have a 35 mm offset, the center of the rim width is 35 mm inboard of the disc to wheel interface. If the B4 GLX wheels also have a 35 mm offset, and the spacer is 1 inch thick, the effective GLX offset will be 10 mm. This much difference from the original geometry will undoubtedly create handling and full lock clearance issues.
Sell the GLX wheels. Use the money for some Honda four bolt alloys.

__________________If the quantity of carbonic acid increases in geometric progression,
the augmentation of the temperature will increase nearly in arithmetic progression.
Svante Arrhenius 1896

I agree with Lug_Nut. Conversion isn't worth contemplating IMO. Find the correct ones and you'll open a bunch of options for yourself including the opportunity to save money. Tons of Civic folks are selling their rims and they'll fit nicely on a B4 4 bolt. Sell the 5 bolts that you have to help fund the rims and you'll likely be better off.

If all you are looking for is 15 inch wheels/tires, try a set of Corrado wheels. Search for a thread on that topic.

I was looking to take the GLX / VR6 Passat alloy rims and mount em on a 96 TDI. I liked their stock look on the Passat. the alloys have a 5 hole pattern and the TDIs the 4 hole. Somebody said something about hub centric? It sounds like a royal pain to otherwise tear apart the tdi guts and buy GLX parts to throw on there. -T

TRH, I still have the Borbets (4x100, 15 inch, et45, with bolts) if you have an interest in a swap. These are not new wheels. One had a slight rim blip. I finally had it straightened last year. Some curb rash on the lips but otherwise in fine condition.
Dieseldorf got them used from someone, before selling them to Natescape, from whom I acquired them. I'd hate to be the last in this chain.

__________________If the quantity of carbonic acid increases in geometric progression,
the augmentation of the temperature will increase nearly in arithmetic progression.
Svante Arrhenius 1896

Another idea:
Have the four bolt hubs and rotors machined for another set of holes making an eight bolt pattern. Pick one existing hole as a start point for an additional 5 bolt pattern. Use holes 1, 3, 5, and 7 for the four bolt GLS wheels, and 1, 2, 4, 6, and 8 for the five bolt GLX wheels.

__________________If the quantity of carbonic acid increases in geometric progression,
the augmentation of the temperature will increase nearly in arithmetic progression.
Svante Arrhenius 1896